U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Powder Mill Group*
  • Modifications:
    • Named
  • Dominant lithology:
    • Basalt
    • Andesite
    • Volcanics
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Hubbard, H.A., 1975, Lower Keweenawan volcanic rocks of Michigan and Wisconsin: U.S. Geological Survey Journal of Research, v. 3, no. 5, p. 529-541.


Summary:

Named for Powder Mill Creek, Gogebic Co., MI. Consists of lower Siemens Creek Formation and upper Kallander Creek Formation; formations are separated by possible unconformity. Group was formerly called South Range Traps by Irving (1883) and was not distinguished from overlying middle Keweenawan rocks by White (1966). Is intruded by Mellen Intrusive Complex (revised) in WI and by diorite on Montreal River, MI, in sec. 17, T47N, R47W. Total thickness of group is about 20,000 ft (6,100 m). Report includes geologic map and correlation chart. Age is Precambrian Y (lower Keweenawan).

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Powder Mill Group*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Cannon, W.F., 1986, Bedrock geologic map of the Iron River 1 degree x 2 degrees quadrangle, Michigan and Wisconsin: U.S. Geological Survey Miscellaneous Investigations Series Map, I-1360-B, 1 sheet, scale 1:250,000 [http://ngmdb.usgs.gov/Prodesc/proddesc_9158.htm]


Summary:

Powder Mill Group with its Siemens Creek Formation and overlying Kallander Creek Formation (by inference only as Kallander Creek Formation is not shown on map) is assigned to Keweenawan Supergroup (lower Keweenawan part) in both northern MI and (also by implication) northern WI.

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Powder Mill Group*
  • Modifications:
    • Age modified
  • AAPG geologic province:
    • Wisconsin arch
Publication:

Cannon, W.F., and Nicholson, S.W., 1992, Revisions of stratigraphic nomenclature within the Keweenawan Supergroup of northern Michigan, IN Cannon, W.F., and Nicholson, S.W., Contributions to the geology and mineral resources of the Midcontinent Rift System: U.S. Geological Survey Bulletin, 1970-A, 8 p.


Summary:

Powder Mill Group and its lower Siemens Creek Formation and upper Kallander Creek Formation are of Middle Proterozoic age. Report includes geologic map and correlation chart.

Source: GNU records (USGS DDS-6; Reston GNULEX).


Search archives

For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Thu 04 Apr 2024 04:06:08 PM MDT